I had bought CyberSync Tx and Rx when they came out. Didn't realized that I had old CST which doens't have the sync in jack. The newer models have it.
Sent email to Paul Buff's company and asked if it is possible to upgrade my CST and how much it will cost.
Got reply back that they are sending a new CST for me and after I get it, I can send back my old version, at no cost to me.
I would say outstanding customer service. Wish other companies treated their customers like this.